Archives

All posts for the month August, 2015

GOES-14 has been out of storage mode and operating in Super Rapid Scan Operations for GOES-R (SRSOR) mode since August 10, providing 1-min imagery. As with past SRSOR data collection periods, the 1-min imagery is available for display in the SPC operational NAWIPS data visualization system. SPC forecasters have been utilizing the imagery in operations when available over relevant areas.

Today (8/18/15) the imagery was especially valuable as GOES-15 (West) underwent a scheduled maneuver, causing a data outage between 1630 and 1759 UTC. More significant to SPC was that GOES-East, to cover for the West outage, operated in Full Disk mode, collecting images only every half hour from 1615 and 1815. This was at a time when convection began to fire ahead and along a cold front passing through an SPC slight risk area across the central US.

The 1-min satellite imagery aided in 2 watch decisions during the early afternoon hours: a severe thunderstorm watch issued at 1815Z over parts of MO/IL, and a tornado watch issued at 1830Z over parts of WI/IA/IL. Cu developing in the clear sky ahead of the front in east-central MO clearly became agitated as a gravity wave feature traversed eastward through 1715Z. Over the next hour, cu quickly evolved into towering cu before eventual initiation took place. Additional development was analyzed further to the north under high clouds near the IA/IL border. Even further north in NE Iowa, strengthening of convection could be seen as bubbling/texture came through a more opaque/smooth cloud shield. Forecasters have commented that the very high temporal restitution satellite imagery allows for easier/more accurate tracking of individual cloud features/structure, especially when partially obscured by upper-level clouds. Evolution of individual features becomes disconnected with longer time between scans, making it difficult to interpret important trend information.

The first animation below shows the 1-min imagery in the time period leading up to and just after initiation during which GOES-East was in Full Disk operations. The second animation shows GOES-East imagery during the same period. SPC watches appear on both. Click animations to enlarge.